The day before serving, preheat the oven to 350 degrees F.
Put the thyme and rosemary on the bottom of a baking sheet. Put the turkey pieces on top, dot with the cubed butter, drizzle with the olive oil and sprinkle with the salt and pepper. Roast, basting from time to time and checking for doneness every 15 minutes after 1 hour of cooking, until the meat reaches 165 degrees F, about 1 1/2 hours. Let rest, covered in foil, for 45 minutes.
Carve the breasts and thighs into slices (keep the legs whole), then arrange on a fresh baking sheet. Cover and refrigerate.
On the day of serving: let the turkey come to room temperature. Preheat the oven to 350 degrees F.
Drizzle the chicken broth over the turkey, cover again with foil and roast until it registers 165 degrees F, about 1 hour.